The present invention relates to a car lifting platform. More particularly, it relates to a car lifting platform wherein the platform mounts to a mast which in turn allows the mounting of the lifting platform to a motorized, heavy-duty piece of equipment, such as a wheel loader.
In certain applications, heavy duty equipment, such as wheel loaders, are used to move and place heavy pieces of machinery. Typically, this heavy machinery is picked up using a fork lift type of attachment. These forks are mounted to a mast which in turn mounts onto the wheel loader.
Specifically in highwall mining operations, conveyor cars (or auger transporting cars) are picked up from a storage area using car lifting platforms and are transported to a launch vehicle where the cars are hooked up to a continuous miner which engages and advances these cars as it mines an ore seam. These cars are typically 40 feet long and quite heavy.
Prior art car lifting platforms used in the highwall mining industry are fabricated from fork-lift forks with flat plates welded in between each fork in order to form a high strength, continuous platform. The fork-lift forks are “L” shaped elements, with one leg of the “L” being shorter and extending in the substantially vertical direction (and referred to as the riser) and the other leg of the “L” being longer and extending in the substantially horizontal direction to form the platform itself.
In prior art car lifting platforms, the flat plates welded between each fork extend only along the horizontal legs of the “L”, stopping just short of the 90 degree angle (hereinafter called the “ell” of the fork) which connects the platform to the risers. This allows dirt or other foreign objects to fall through the forks in order to keep the platform clean. It also permits a locating tab or pawl, projecting from the car or other object being lifted, to engage the opening between two of the forks in order to limit the amount of slipping (along the longitudinal axis of the car) allowed of the car during transportation.
In the prior art design, the ells are the point of stress concentration of these car lifting platforms. Fatigue cracks develop at these stress points, and, in short order, the fatigue cracks propagate and the forks break.